src/plugins/nat/out2in_ed.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 endpoint-dependent outside to inside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/pg/pg.h>
  23 #include <vnet/ip/ip.h>
  24 #include <vnet/ethernet/ethernet.h>
  25 #include <vnet/fib/ip4_fib.h>
  26 #include <vnet/udp/udp.h>
  27 #include <vppinfra/error.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_reass.h>
  31 #include <nat/nat_inlines.h>
  32
  33 #define foreach_nat_out2in_ed_error                     \
  34 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
  35 _(OUT2IN_PACKETS, "Good out2in packets processed")      \
  36 _(OUT_OF_PORTS, "Out of ports")                         \
  37 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
  38 _(NO_TRANSLATION, "No translation")                     \
  39 _(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded")   \
  40 _(DROP_FRAGMENT, "Drop fragment")                       \
  41 _(MAX_REASS, "Maximum reassemblies exceeded")           \
  42 _(MAX_FRAG, "Maximum fragments per reassembly exceeded")
  43
  44 typedef enum
  45 {
  46 #define _(sym,str) NAT_OUT2IN_ED_ERROR_##sym,
  47   foreach_nat_out2in_ed_error
  48 #undef _
  49     NAT_OUT2IN_ED_N_ERROR,
  50 } nat_out2in_ed_error_t;
  51
  52 static char *nat_out2in_ed_error_strings[] = {
  53 #define _(sym,string) string,
  54   foreach_nat_out2in_ed_error
  55 #undef _
  56 };
  57
  58 typedef enum
  59 {
  60   NAT44_ED_OUT2IN_NEXT_DROP,
  61   NAT44_ED_OUT2IN_NEXT_LOOKUP,
  62   NAT44_ED_OUT2IN_NEXT_ICMP_ERROR,
  63   NAT44_ED_OUT2IN_NEXT_IN2OUT,
  64   NAT44_ED_OUT2IN_NEXT_SLOW_PATH,
  65   NAT44_ED_OUT2IN_NEXT_REASS,
  66   NAT44_ED_OUT2IN_N_NEXT,
  67 } nat44_ed_out2in_next_t;
  68
  69 typedef struct
  70 {
  71   u32 sw_if_index;
  72   u32 next_index;
  73   u32 session_index;
  74   u32 is_slow_path;
  75 } nat44_ed_out2in_trace_t;
  76
  77 vlib_node_registration_t nat44_ed_out2in_node;
  78 vlib_node_registration_t nat44_ed_out2in_slowpath_node;
  79 vlib_node_registration_t nat44_ed_out2in_reass_node;
  80
  81 static u8 *
  82 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  83 {
  84   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  85   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  86   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  87   char *tag;
  88
  89   tag =
  90     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  91     "NAT44_OUT2IN_ED_FAST_PATH";
  92
  93   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  94               t->sw_if_index, t->next_index, t->session_index);
  95
  96   return s;
  97 }
  98
  99 static inline u32
 100 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 101                           ip4_header_t * ip0, icmp46_header_t * icmp0,
 102                           u32 sw_if_index0, u32 rx_fib_index0,
 103                           vlib_node_runtime_t * node, u32 next0, f64 now,
 104                           u32 thread_index, snat_session_t ** p_s0)
 105 {
 106   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 107                        next0, thread_index, p_s0, 0);
 108   snat_session_t *s0 = *p_s0;
 109   if (PREDICT_TRUE (next0 != NAT44_ED_OUT2IN_NEXT_DROP && s0))
 110     {
 111       /* Accounting */
 112       nat44_session_update_counters (s0, now,
 113                                      vlib_buffer_length_in_chain
 114                                      (sm->vlib_main, b0));
 115       /* Per-user LRU list maintenance */
 116       nat44_session_update_lru (sm, s0, thread_index);
 117     }
 118   return next0;
 119 }
 120
 121 int
 122 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
 123 {
 124   snat_main_t *sm = &snat_main;
 125   nat44_is_idle_session_ctx_t *ctx = arg;
 126   snat_session_t *s;
 127   u64 sess_timeout_time;
 128   nat_ed_ses_key_t ed_key;
 129   clib_bihash_kv_16_8_t ed_kv;
 130   int i;
 131   snat_address_t *a;
 132   snat_session_key_t key;
 133   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 134                                                        ctx->thread_index);
 135
 136   s = pool_elt_at_index (tsm->sessions, kv->value);
 137   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 138   if (ctx->now >= sess_timeout_time)
 139     {
 140       ed_key.l_addr = s->in2out.addr;
 141       ed_key.r_addr = s->ext_host_addr;
 142       ed_key.fib_index = s->in2out.fib_index;
 143       if (snat_is_unk_proto_session (s))
 144         {
 145           ed_key.proto = s->in2out.port;
 146           ed_key.r_port = 0;
 147           ed_key.l_port = 0;
 148         }
 149       else
 150         {
 151           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 152           ed_key.l_port = s->in2out.port;
 153           ed_key.r_port = s->ext_host_port;
 154         }
 155       if (is_twice_nat_session (s))
 156         {
 157           ed_key.r_addr = s->ext_host_nat_addr;
 158           ed_key.r_port = s->ext_host_nat_port;
 159         }
 160       ed_kv.key[0] = ed_key.as_u64[0];
 161       ed_kv.key[1] = ed_key.as_u64[1];
 162       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 163         nat_log_warn ("in2out_ed key del failed");
 164
 165       if (snat_is_unk_proto_session (s))
 166         goto delete;
 167
 168       snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
 169                                            s->out2in.addr.as_u32,
 170                                            s->in2out.protocol,
 171                                            s->in2out.port,
 172                                            s->out2in.port,
 173                                            s->in2out.fib_index);
 174
 175       if (is_twice_nat_session (s))
 176         {
 177           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 178             {
 179               key.protocol = s->in2out.protocol;
 180               key.port = s->ext_host_nat_port;
 181               a = sm->twice_nat_addresses + i;
 182               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 183                 {
 184                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 185                                                       ctx->thread_index,
 186                                                       &key);
 187                   break;
 188                 }
 189             }
 190         }
 191
 192       if (snat_is_session_static (s))
 193         goto delete;
 194
 195       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 196                                           &s->out2in);
 197     delete:
 198       nat44_delete_session (sm, s, ctx->thread_index);
 199       return 1;
 200     }
 201
 202   return 0;
 203 }
 204
 205 static snat_session_t *
 206 create_session_for_static_mapping_ed (snat_main_t * sm,
 207                                       vlib_buffer_t * b,
 208                                       snat_session_key_t l_key,
 209                                       snat_session_key_t e_key,
 210                                       vlib_node_runtime_t * node,
 211                                       u32 thread_index,
 212                                       twice_nat_type_t twice_nat,
 213                                       lb_nat_type_t lb_nat, f64 now)
 214 {
 215   snat_session_t *s;
 216   snat_user_t *u;
 217   ip4_header_t *ip;
 218   udp_header_t *udp;
 219   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 220   clib_bihash_kv_16_8_t kv;
 221   snat_session_key_t eh_key;
 222   nat44_is_idle_session_ctx_t ctx;
 223
 224   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 225     {
 226       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 227       nat_log_notice ("maximum sessions exceeded");
 228       return 0;
 229     }
 230
 231   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 232   if (!u)
 233     {
 234       nat_log_warn ("create NAT user failed");
 235       return 0;
 236     }
 237
 238   s = nat_ed_session_alloc (sm, u, thread_index, now);
 239   if (!s)
 240     {
 241       nat44_delete_user_with_no_session (sm, u, thread_index);
 242       nat_log_warn ("create NAT session failed");
 243       return 0;
 244     }
 245
 246   ip = vlib_buffer_get_current (b);
 247   udp = ip4_next_header (ip);
 248
 249   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 250   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 251   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 252   if (lb_nat)
 253     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 254   if (lb_nat == AFFINITY_LB_NAT)
 255     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 256   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 257   s->out2in = e_key;
 258   s->in2out = l_key;
 259   s->in2out.protocol = s->out2in.protocol;
 260   user_session_increment (sm, u, 1);
 261
 262   /* Add to lookup tables */
 263   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 264               e_key.fib_index, e_key.port, s->ext_host_port);
 265   kv.value = s - tsm->sessions;
 266   ctx.now = now;
 267   ctx.thread_index = thread_index;
 268   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 269                                                nat44_o2i_ed_is_idle_session_cb,
 270                                                &ctx))
 271     nat_log_notice ("out2in-ed key add failed");
 272
 273   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 274                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 275     {
 276       eh_key.protocol = e_key.protocol;
 277       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 278                                                thread_index, &eh_key,
 279                                                sm->port_per_thread,
 280                                                tsm->snat_thread_index))
 281         {
 282           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 283           nat44_delete_session (sm, s, thread_index);
 284           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 285             nat_log_notice ("out2in-ed key del failed");
 286           return 0;
 287         }
 288       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 289       s->ext_host_nat_port = eh_key.port;
 290       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 291       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 292                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 293     }
 294   else
 295     {
 296       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 297                   l_key.fib_index, l_key.port, s->ext_host_port);
 298     }
 299   kv.value = s - tsm->sessions;
 300   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 301                                                nat44_i2o_ed_is_idle_session_cb,
 302                                                &ctx))
 303     nat_log_notice ("in2out-ed key add failed");
 304
 305   return s;
 306 }
 307
 308 static_always_inline int
 309 icmp_get_ed_key (ip4_header_t * ip0, nat_ed_ses_key_t * p_key0)
 310 {
 311   icmp46_header_t *icmp0;
 312   nat_ed_ses_key_t key0;
 313   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 314   ip4_header_t *inner_ip0;
 315   void *l4_header = 0;
 316   icmp46_header_t *inner_icmp0;
 317
 318   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 319   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 320
 321   if (!icmp_is_error_message (icmp0))
 322     {
 323       key0.proto = IP_PROTOCOL_ICMP;
 324       key0.l_addr = ip0->dst_address;
 325       key0.r_addr = ip0->src_address;
 326       key0.l_port = echo0->identifier;
 327       key0.r_port = 0;
 328     }
 329   else
 330     {
 331       inner_ip0 = (ip4_header_t *) (echo0 + 1);
 332       l4_header = ip4_next_header (inner_ip0);
 333       key0.proto = inner_ip0->protocol;
 334       key0.l_addr = inner_ip0->src_address;
 335       key0.r_addr = inner_ip0->dst_address;
 336       switch (ip_proto_to_snat_proto (inner_ip0->protocol))
 337         {
 338         case SNAT_PROTOCOL_ICMP:
 339           inner_icmp0 = (icmp46_header_t *) l4_header;
 340           inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 341           key0.l_port = inner_echo0->identifier;
 342           key0.r_port = 0;
 343           break;
 344         case SNAT_PROTOCOL_UDP:
 345         case SNAT_PROTOCOL_TCP:
 346           key0.l_port = ((tcp_udp_header_t *) l4_header)->src_port;
 347           key0.r_port = ((tcp_udp_header_t *) l4_header)->dst_port;
 348           break;
 349         default:
 350           return -1;
 351         }
 352     }
 353   *p_key0 = key0;
 354   return 0;
 355 }
 356
 357 static int
 358 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 359               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 360 {
 361   clib_bihash_kv_16_8_t kv, value;
 362   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 363
 364   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 365               rx_fib_index, src_port, dst_port);
 366   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 367     return 1;
 368
 369   return 0;
 370 }
 371
 372 static void
 373 create_bypass_for_fwd (snat_main_t * sm, ip4_header_t * ip, u32 rx_fib_index,
 374                        u32 thread_index)
 375 {
 376   nat_ed_ses_key_t key;
 377   clib_bihash_kv_16_8_t kv, value;
 378   udp_header_t *udp;
 379   snat_user_t *u;
 380   snat_session_t *s = 0;
 381   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 382   f64 now = vlib_time_now (sm->vlib_main);
 383
 384   if (ip->protocol == IP_PROTOCOL_ICMP)
 385     {
 386       if (icmp_get_ed_key (ip, &key))
 387         return;
 388     }
 389   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 390     {
 391       udp = ip4_next_header (ip);
 392       key.r_addr = ip->src_address;
 393       key.l_addr = ip->dst_address;
 394       key.proto = ip->protocol;
 395       key.l_port = udp->dst_port;
 396       key.r_port = udp->src_port;
 397     }
 398   else
 399     {
 400       key.r_addr = ip->src_address;
 401       key.l_addr = ip->dst_address;
 402       key.proto = ip->protocol;
 403       key.l_port = key.r_port = 0;
 404     }
 405   key.fib_index = 0;
 406   kv.key[0] = key.as_u64[0];
 407   kv.key[1] = key.as_u64[1];
 408
 409   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 410     {
 411       s = pool_elt_at_index (tsm->sessions, value.value);
 412     }
 413   else
 414     {
 415       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 416         return;
 417
 418       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 419                                   thread_index);
 420       if (!u)
 421         {
 422           nat_log_warn ("create NAT user failed");
 423           return;
 424         }
 425
 426       s = nat_ed_session_alloc (sm, u, thread_index, now);
 427       if (!s)
 428         {
 429           nat44_delete_user_with_no_session (sm, u, thread_index);
 430           nat_log_warn ("create NAT session failed");
 431           return;
 432         }
 433
 434       s->ext_host_addr = key.r_addr;
 435       s->ext_host_port = key.r_port;
 436       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 437       s->out2in.addr = key.l_addr;
 438       s->out2in.port = key.l_port;
 439       s->out2in.protocol = ip_proto_to_snat_proto (key.proto);
 440       s->out2in.fib_index = 0;
 441       s->in2out = s->out2in;
 442       user_session_increment (sm, u, 0);
 443
 444       kv.value = s - tsm->sessions;
 445       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 446         nat_log_notice ("in2out_ed key add failed");
 447     }
 448
 449   if (ip->protocol == IP_PROTOCOL_TCP)
 450     {
 451       tcp_header_t *tcp = ip4_next_header (ip);
 452       if (nat44_set_tcp_session_state_o2i (sm, s, tcp, thread_index))
 453         return;
 454     }
 455
 456   /* Accounting */
 457   nat44_session_update_counters (s, now, 0);
 458   /* Per-user LRU list maintenance */
 459   nat44_session_update_lru (sm, s, thread_index);
 460 }
 461
 462 u32
 463 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 464                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 465                       u8 * p_proto, snat_session_key_t * p_value,
 466                       u8 * p_dont_translate, void *d, void *e)
 467 {
 468   u32 next = ~0, sw_if_index, rx_fib_index;
 469   icmp46_header_t *icmp;
 470   nat_ed_ses_key_t key;
 471   clib_bihash_kv_16_8_t kv, value;
 472   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 473   snat_session_t *s = 0;
 474   u8 dont_translate = 0, is_addr_only, identity_nat;
 475   snat_session_key_t e_key, l_key;
 476
 477   icmp = (icmp46_header_t *) ip4_next_header (ip);
 478   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 479   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 480
 481   if (icmp_get_ed_key (ip, &key))
 482     {
 483       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 484       next = NAT44_ED_OUT2IN_NEXT_DROP;
 485       goto out;
 486     }
 487   key.fib_index = rx_fib_index;
 488   kv.key[0] = key.as_u64[0];
 489   kv.key[1] = key.as_u64[1];
 490
 491   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 492     {
 493       /* Try to match static mapping */
 494       e_key.addr = ip->dst_address;
 495       e_key.port = key.l_port;
 496       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 497       e_key.fib_index = rx_fib_index;
 498       if (snat_static_mapping_match
 499           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 500         {
 501           if (!sm->forwarding_enabled)
 502             {
 503               /* Don't NAT packet aimed at the intfc address */
 504               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 505                                                     ip->dst_address.as_u32)))
 506                 {
 507                   dont_translate = 1;
 508                   goto out;
 509                 }
 510               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 511               next = NAT44_ED_OUT2IN_NEXT_DROP;
 512               goto out;
 513             }
 514           else
 515             {
 516               dont_translate = 1;
 517               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 518                                 thread_index, rx_fib_index))
 519                 {
 520                   next = NAT44_ED_OUT2IN_NEXT_IN2OUT;
 521                   goto out;
 522                 }
 523               create_bypass_for_fwd (sm, ip, rx_fib_index, thread_index);
 524               goto out;
 525             }
 526         }
 527
 528       if (PREDICT_FALSE (icmp->type != ICMP4_echo_reply &&
 529                          (icmp->type != ICMP4_echo_request || !is_addr_only)))
 530         {
 531           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 532           next = NAT44_ED_OUT2IN_NEXT_DROP;
 533           goto out;
 534         }
 535
 536       if (PREDICT_FALSE (identity_nat))
 537         {
 538           dont_translate = 1;
 539           goto out;
 540         }
 541
 542       /* Create session initiated by host from external network */
 543       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 544                                                 thread_index, 0, 0,
 545                                                 vlib_time_now
 546                                                 (sm->vlib_main));
 547
 548       if (!s)
 549         {
 550           next = NAT44_ED_OUT2IN_NEXT_DROP;
 551           goto out;
 552         }
 553     }
 554   else
 555     {
 556       if (PREDICT_FALSE (icmp->type != ICMP4_echo_reply &&
 557                          icmp->type != ICMP4_echo_request &&
 558                          !icmp_is_error_message (icmp)))
 559         {
 560           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 561           next = NAT44_ED_OUT2IN_NEXT_DROP;
 562           goto out;
 563         }
 564
 565       s = pool_elt_at_index (tsm->sessions, value.value);
 566     }
 567
 568   *p_proto = ip_proto_to_snat_proto (key.proto);
 569 out:
 570   if (s)
 571     *p_value = s->in2out;
 572   *p_dont_translate = dont_translate;
 573   if (d)
 574     *(snat_session_t **) d = s;
 575   return next;
 576 }
 577
 578 static snat_session_t *
 579 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 580                                vlib_buffer_t * b,
 581                                ip4_header_t * ip,
 582                                u32 rx_fib_index,
 583                                u32 thread_index,
 584                                f64 now,
 585                                vlib_main_t * vm, vlib_node_runtime_t * node)
 586 {
 587   clib_bihash_kv_8_8_t kv, value;
 588   clib_bihash_kv_16_8_t s_kv, s_value;
 589   snat_static_mapping_t *m;
 590   u32 old_addr, new_addr;
 591   ip_csum_t sum;
 592   snat_session_t *s;
 593   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 594   snat_user_t *u;
 595
 596   old_addr = ip->dst_address.as_u32;
 597
 598   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 599               rx_fib_index, 0, 0);
 600
 601   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 602     {
 603       s = pool_elt_at_index (tsm->sessions, s_value.value);
 604       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 605     }
 606   else
 607     {
 608       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 609         {
 610           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 611           nat_log_notice ("maximum sessions exceeded");
 612           return 0;
 613         }
 614
 615       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 616       if (clib_bihash_search_8_8
 617           (&sm->static_mapping_by_external, &kv, &value))
 618         {
 619           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 620           return 0;
 621         }
 622
 623       m = pool_elt_at_index (sm->static_mappings, value.value);
 624
 625       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 626
 627       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 628                                   thread_index);
 629       if (!u)
 630         {
 631           nat_log_warn ("create NAT user failed");
 632           return 0;
 633         }
 634
 635       /* Create a new session */
 636       s = nat_ed_session_alloc (sm, u, thread_index, now);
 637       if (!s)
 638         {
 639           nat44_delete_user_with_no_session (sm, u, thread_index);
 640           nat_log_warn ("create NAT session failed");
 641           return 0;
 642         }
 643
 644       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 645       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 646       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 647       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 648       s->out2in.addr.as_u32 = old_addr;
 649       s->out2in.fib_index = rx_fib_index;
 650       s->in2out.addr.as_u32 = new_addr;
 651       s->in2out.fib_index = m->fib_index;
 652       s->in2out.port = s->out2in.port = ip->protocol;
 653       user_session_increment (sm, u, 1);
 654
 655       /* Add to lookup tables */
 656       s_kv.value = s - tsm->sessions;
 657       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 658         nat_log_notice ("out2in key add failed");
 659
 660       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 661                   m->fib_index, 0, 0);
 662       s_kv.value = s - tsm->sessions;
 663       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 664         nat_log_notice ("in2out key add failed");
 665     }
 666
 667   /* Update IP checksum */
 668   sum = ip->checksum;
 669   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 670   ip->checksum = ip_csum_fold (sum);
 671
 672   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 673
 674   /* Accounting */
 675   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b));
 676   /* Per-user LRU list maintenance */
 677   nat44_session_update_lru (sm, s, thread_index);
 678
 679   return s;
 680 }
 681
 682 static inline uword
 683 nat44_ed_out2in_node_fn_inline (vlib_main_t * vm,
 684                                 vlib_node_runtime_t * node,
 685                                 vlib_frame_t * frame, int is_slow_path)
 686 {
 687   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 688   nat44_ed_out2in_next_t next_index;
 689   snat_main_t *sm = &snat_main;
 690   f64 now = vlib_time_now (vm);
 691   u32 thread_index = vm->thread_index;
 692   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 693
 694   stats_node_index = is_slow_path ? nat44_ed_out2in_slowpath_node.index :
 695     nat44_ed_out2in_node.index;
 696
 697   from = vlib_frame_vector_args (frame);
 698   n_left_from = frame->n_vectors;
 699   next_index = node->cached_next_index;
 700
 701   while (n_left_from > 0)
 702     {
 703       u32 n_left_to_next;
 704
 705       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 706
 707       while (n_left_from >= 4 && n_left_to_next >= 2)
 708         {
 709           u32 bi0, bi1;
 710           vlib_buffer_t *b0, *b1;
 711           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 712             new_addr0;
 713           u32 next1, sw_if_index1, rx_fib_index1, proto1, old_addr1,
 714             new_addr1;
 715           u16 old_port0, new_port0, old_port1, new_port1;
 716           ip4_header_t *ip0, *ip1;
 717           udp_header_t *udp0, *udp1;
 718           tcp_header_t *tcp0, *tcp1;
 719           icmp46_header_t *icmp0, *icmp1;
 720           snat_session_t *s0 = 0, *s1 = 0;
 721           clib_bihash_kv_16_8_t kv0, value0, kv1, value1;
 722           ip_csum_t sum0, sum1;
 723           snat_session_key_t e_key0, l_key0, e_key1, l_key1;
 724           lb_nat_type_t lb_nat0, lb_nat1;
 725           twice_nat_type_t twice_nat0, twice_nat1;
 726           u8 identity_nat0, identity_nat1;
 727
 728           /* Prefetch next iteration. */
 729           {
 730             vlib_buffer_t *p2, *p3;
 731
 732             p2 = vlib_get_buffer (vm, from[2]);
 733             p3 = vlib_get_buffer (vm, from[3]);
 734
 735             vlib_prefetch_buffer_header (p2, LOAD);
 736             vlib_prefetch_buffer_header (p3, LOAD);
 737
 738             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 739             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 740           }
 741
 742           /* speculatively enqueue b0 and b1 to the current next frame */
 743           to_next[0] = bi0 = from[0];
 744           to_next[1] = bi1 = from[1];
 745           from += 2;
 746           to_next += 2;
 747           n_left_from -= 2;
 748           n_left_to_next -= 2;
 749
 750           b0 = vlib_get_buffer (vm, bi0);
 751           b1 = vlib_get_buffer (vm, bi1);
 752
 753           next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
 754           vnet_buffer (b0)->snat.flags = 0;
 755           ip0 = vlib_buffer_get_current (b0);
 756
 757           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 758           rx_fib_index0 =
 759             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 760                                                  sw_if_index0);
 761
 762           if (PREDICT_FALSE (ip0->ttl == 1))
 763             {
 764               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 765               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 766                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 767                                            0);
 768               next0 = NAT44_ED_OUT2IN_NEXT_ICMP_ERROR;
 769               goto trace00;
 770             }
 771
 772           udp0 = ip4_next_header (ip0);
 773           tcp0 = (tcp_header_t *) udp0;
 774           icmp0 = (icmp46_header_t *) udp0;
 775           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 776
 777           if (is_slow_path)
 778             {
 779               if (PREDICT_FALSE (proto0 == ~0))
 780                 {
 781                   s0 =
 782                     nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 783                                                    thread_index, now, vm,
 784                                                    node);
 785                   if (!sm->forwarding_enabled)
 786                     {
 787                       if (!s0)
 788                         next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 789                       goto trace00;
 790                     }
 791                 }
 792
 793               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 794                 {
 795                   next0 = icmp_out2in_ed_slow_path
 796                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 797                      next0, now, thread_index, &s0);
 798                   goto trace00;
 799                 }
 800             }
 801           else
 802             {
 803               if (PREDICT_FALSE (proto0 == ~0))
 804                 {
 805                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
 806                   goto trace00;
 807                 }
 808
 809               if (ip4_is_fragment (ip0))
 810                 {
 811                   next0 = NAT44_ED_OUT2IN_NEXT_REASS;
 812                   goto trace00;
 813                 }
 814
 815               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 816                 {
 817                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
 818                   goto trace00;
 819                 }
 820             }
 821
 822           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 823                       ip0->protocol, rx_fib_index0, udp0->dst_port,
 824                       udp0->src_port);
 825
 826           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 827             {
 828               if (is_slow_path)
 829                 {
 830                   /* Try to match static mapping by external address and port,
 831                      destination address and port in packet */
 832                   e_key0.addr = ip0->dst_address;
 833                   e_key0.port = udp0->dst_port;
 834                   e_key0.protocol = proto0;
 835                   e_key0.fib_index = rx_fib_index0;
 836                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
 837                                                  &twice_nat0, &lb_nat0,
 838                                                  &ip0->src_address,
 839                                                  &identity_nat0))
 840                     {
 841                       /*
 842                        * Send DHCP packets to the ipv4 stack, or we won't
 843                        * be able to use dhcp client on the outside interface
 844                        */
 845                       if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
 846                                          && (udp0->dst_port ==
 847                                              clib_host_to_net_u16
 848                                              (UDP_DST_PORT_dhcp_to_client))))
 849                         {
 850                           vnet_feature_next (&next0, b0);
 851                           goto trace00;
 852                         }
 853
 854                       if (!sm->forwarding_enabled)
 855                         {
 856                           b0->error =
 857                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 858                           next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 859                         }
 860                       else
 861                         {
 862                           if (next_src_nat (sm, ip0, ip0->protocol,
 863                                             udp0->src_port, udp0->dst_port,
 864                                             thread_index, rx_fib_index0))
 865                             {
 866                               next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
 867                               goto trace00;
 868                             }
 869                           create_bypass_for_fwd (sm, ip0, rx_fib_index0,
 870                                                  thread_index);
 871                         }
 872                       goto trace00;
 873                     }
 874
 875                   if (PREDICT_FALSE (identity_nat0))
 876                     goto trace00;
 877
 878                   /* Create session initiated by host from external network */
 879                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
 880                                                              e_key0, node,
 881                                                              thread_index,
 882                                                              twice_nat0,
 883                                                              lb_nat0, now);
 884
 885                   if (!s0)
 886                     {
 887                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 888                       goto trace00;
 889                     }
 890                 }
 891               else
 892                 {
 893                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
 894                   goto trace00;
 895                 }
 896             }
 897           else
 898             {
 899               s0 = pool_elt_at_index (tsm->sessions, value0.value);
 900             }
 901
 902           old_addr0 = ip0->dst_address.as_u32;
 903           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 904           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 905
 906           sum0 = ip0->checksum;
 907           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 908                                  dst_address);
 909           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 910             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 911                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 912                                    src_address);
 913           ip0->checksum = ip_csum_fold (sum0);
 914
 915           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 916             {
 917               old_port0 = tcp0->dst_port;
 918               new_port0 = tcp0->dst_port = s0->in2out.port;
 919
 920               sum0 = tcp0->checksum;
 921               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 922                                      dst_address);
 923               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 924                                      length);
 925               if (is_twice_nat_session (s0))
 926                 {
 927                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 928                                          s0->ext_host_nat_addr.as_u32,
 929                                          ip4_header_t, dst_address);
 930                   sum0 = ip_csum_update (sum0, tcp0->src_port,
 931                                          s0->ext_host_nat_port, ip4_header_t,
 932                                          length);
 933                   tcp0->src_port = s0->ext_host_nat_port;
 934                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 935                 }
 936               tcp0->checksum = ip_csum_fold (sum0);
 937               if (nat44_set_tcp_session_state_o2i
 938                   (sm, s0, tcp0, thread_index))
 939                 goto trace00;
 940             }
 941           else
 942             {
 943               udp0->dst_port = s0->in2out.port;
 944               if (is_twice_nat_session (s0))
 945                 {
 946                   udp0->src_port = s0->ext_host_nat_port;
 947                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 948                 }
 949               udp0->checksum = 0;
 950             }
 951
 952           /* Accounting */
 953           nat44_session_update_counters (s0, now,
 954                                          vlib_buffer_length_in_chain (vm,
 955                                                                       b0));
 956           /* Per-user LRU list maintenance */
 957           nat44_session_update_lru (sm, s0, thread_index);
 958
 959         trace00:
 960           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 961                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 962             {
 963               nat44_ed_out2in_trace_t *t =
 964                 vlib_add_trace (vm, node, b0, sizeof (*t));
 965               t->is_slow_path = is_slow_path;
 966               t->sw_if_index = sw_if_index0;
 967               t->next_index = next0;
 968               t->session_index = ~0;
 969               if (s0)
 970                 t->session_index = s0 - tsm->sessions;
 971             }
 972
 973           pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP;
 974
 975           next1 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
 976           vnet_buffer (b1)->snat.flags = 0;
 977           ip1 = vlib_buffer_get_current (b1);
 978
 979           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
 980           rx_fib_index1 =
 981             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 982                                                  sw_if_index1);
 983
 984           if (PREDICT_FALSE (ip1->ttl == 1))
 985             {
 986               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 987               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
 988                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 989                                            0);
 990               next1 = NAT44_ED_OUT2IN_NEXT_ICMP_ERROR;
 991               goto trace01;
 992             }
 993
 994           udp1 = ip4_next_header (ip1);
 995           tcp1 = (tcp_header_t *) udp1;
 996           icmp1 = (icmp46_header_t *) udp1;
 997           proto1 = ip_proto_to_snat_proto (ip1->protocol);
 998
 999           if (is_slow_path)
1000             {
1001               if (PREDICT_FALSE (proto1 == ~0))
1002                 {
1003                   s1 =
1004                     nat44_ed_out2in_unknown_proto (sm, b1, ip1, rx_fib_index1,
1005                                                    thread_index, now, vm,
1006                                                    node);
1007                   if (!sm->forwarding_enabled)
1008                     {
1009                       if (!s1)
1010                         next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1011                       goto trace01;
1012                     }
1013                 }
1014
1015               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1016                 {
1017                   next1 = icmp_out2in_ed_slow_path
1018                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1019                      next1, now, thread_index, &s1);
1020                   goto trace01;
1021                 }
1022             }
1023           else
1024             {
1025               if (PREDICT_FALSE (proto1 == ~0))
1026                 {
1027                   next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1028                   goto trace01;
1029                 }
1030
1031               if (ip4_is_fragment (ip1))
1032                 {
1033                   next1 = NAT44_ED_OUT2IN_NEXT_REASS;
1034                   goto trace01;
1035                 }
1036
1037               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1038                 {
1039                   next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1040                   goto trace01;
1041                 }
1042             }
1043
1044           make_ed_kv (&kv1, &ip1->dst_address, &ip1->src_address,
1045                       ip1->protocol, rx_fib_index1, udp1->dst_port,
1046                       udp1->src_port);
1047
1048           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv1, &value1))
1049             {
1050               if (is_slow_path)
1051                 {
1052                   /* Try to match static mapping by external address and port,
1053                      destination address and port in packet */
1054                   e_key1.addr = ip1->dst_address;
1055                   e_key1.port = udp1->dst_port;
1056                   e_key1.protocol = proto1;
1057                   e_key1.fib_index = rx_fib_index1;
1058                   if (snat_static_mapping_match (sm, e_key1, &l_key1, 1, 0,
1059                                                  &twice_nat1, &lb_nat1,
1060                                                  &ip1->src_address,
1061                                                  &identity_nat1))
1062                     {
1063                       /*
1064                        * Send DHCP packets to the ipv4 stack, or we won't
1065                        * be able to use dhcp client on the outside interface
1066                        */
1067                       if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_UDP
1068                                          && (udp1->dst_port ==
1069                                              clib_host_to_net_u16
1070                                              (UDP_DST_PORT_dhcp_to_client))))
1071                         {
1072                           vnet_feature_next (&next1, b1);
1073                           goto trace01;
1074                         }
1075
1076                       if (!sm->forwarding_enabled)
1077                         {
1078                           b1->error =
1079                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1080                           next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1081                         }
1082                       else
1083                         {
1084                           if (next_src_nat (sm, ip1, ip1->protocol,
1085                                             udp1->src_port, udp1->dst_port,
1086                                             thread_index, rx_fib_index1))
1087                             {
1088                               next1 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
1089                               goto trace01;
1090                             }
1091                           create_bypass_for_fwd (sm, ip1, rx_fib_index1,
1092                                                  thread_index);
1093                         }
1094                       goto trace01;
1095                     }
1096
1097                   if (PREDICT_FALSE (identity_nat1))
1098                     goto trace01;
1099
1100                   /* Create session initiated by host from external network */
1101                   s1 = create_session_for_static_mapping_ed (sm, b1, l_key1,
1102                                                              e_key1, node,
1103                                                              thread_index,
1104                                                              twice_nat1,
1105                                                              lb_nat1, now);
1106
1107                   if (!s1)
1108                     {
1109                       next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1110                       goto trace01;
1111                     }
1112                 }
1113               else
1114                 {
1115                   next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1116                   goto trace01;
1117                 }
1118             }
1119           else
1120             {
1121               s1 = pool_elt_at_index (tsm->sessions, value1.value);
1122             }
1123
1124           old_addr1 = ip1->dst_address.as_u32;
1125           new_addr1 = ip1->dst_address.as_u32 = s1->in2out.addr.as_u32;
1126           vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->in2out.fib_index;
1127
1128           sum1 = ip1->checksum;
1129           sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1130                                  dst_address);
1131           if (PREDICT_FALSE (is_twice_nat_session (s1)))
1132             sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1133                                    s1->ext_host_nat_addr.as_u32, ip4_header_t,
1134                                    src_address);
1135           ip1->checksum = ip_csum_fold (sum1);
1136
1137           if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
1138             {
1139               old_port1 = tcp1->dst_port;
1140               new_port1 = tcp1->dst_port = s1->in2out.port;
1141
1142               sum1 = tcp1->checksum;
1143               sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1144                                      dst_address);
1145               sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
1146                                      length);
1147               if (is_twice_nat_session (s1))
1148                 {
1149                   sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1150                                          s1->ext_host_nat_addr.as_u32,
1151                                          ip4_header_t, dst_address);
1152                   sum1 = ip_csum_update (sum1, tcp1->src_port,
1153                                          s1->ext_host_nat_port, ip4_header_t,
1154                                          length);
1155                   tcp1->src_port = s1->ext_host_nat_port;
1156                   ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
1157                 }
1158               tcp1->checksum = ip_csum_fold (sum1);
1159               if (nat44_set_tcp_session_state_o2i
1160                   (sm, s1, tcp1, thread_index))
1161                 goto trace01;
1162             }
1163           else
1164             {
1165               udp1->dst_port = s1->in2out.port;
1166               if (is_twice_nat_session (s1))
1167                 {
1168                   udp1->src_port = s1->ext_host_nat_port;
1169                   ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
1170                 }
1171               udp1->checksum = 0;
1172             }
1173
1174           /* Accounting */
1175           nat44_session_update_counters (s1, now,
1176                                          vlib_buffer_length_in_chain (vm,
1177                                                                       b1));
1178           /* Per-user LRU list maintenance */
1179           nat44_session_update_lru (sm, s1, thread_index);
1180
1181         trace01:
1182           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1183                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1184             {
1185               nat44_ed_out2in_trace_t *t =
1186                 vlib_add_trace (vm, node, b1, sizeof (*t));
1187               t->is_slow_path = is_slow_path;
1188               t->sw_if_index = sw_if_index1;
1189               t->next_index = next1;
1190               t->session_index = ~0;
1191               if (s1)
1192                 t->session_index = s1 - tsm->sessions;
1193             }
1194
1195           pkts_processed += next1 != NAT44_ED_OUT2IN_NEXT_DROP;
1196
1197           /* verify speculative enqueues, maybe switch current next frame */
1198           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1199                                            to_next, n_left_to_next,
1200                                            bi0, bi1, next0, next1);
1201         }
1202
1203       while (n_left_from > 0 && n_left_to_next > 0)
1204         {
1205           u32 bi0;
1206           vlib_buffer_t *b0;
1207           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
1208             new_addr0;
1209           u16 old_port0, new_port0;
1210           ip4_header_t *ip0;
1211           udp_header_t *udp0;
1212           tcp_header_t *tcp0;
1213           icmp46_header_t *icmp0;
1214           snat_session_t *s0 = 0;
1215           clib_bihash_kv_16_8_t kv0, value0;
1216           ip_csum_t sum0;
1217           snat_session_key_t e_key0, l_key0;
1218           lb_nat_type_t lb_nat0;
1219           twice_nat_type_t twice_nat0;
1220           u8 identity_nat0;
1221
1222           /* speculatively enqueue b0 to the current next frame */
1223           bi0 = from[0];
1224           to_next[0] = bi0;
1225           from += 1;
1226           to_next += 1;
1227           n_left_from -= 1;
1228           n_left_to_next -= 1;
1229
1230           b0 = vlib_get_buffer (vm, bi0);
1231           next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
1232           vnet_buffer (b0)->snat.flags = 0;
1233           ip0 = vlib_buffer_get_current (b0);
1234
1235           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1236           rx_fib_index0 =
1237             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1238                                                  sw_if_index0);
1239
1240           if (PREDICT_FALSE (ip0->ttl == 1))
1241             {
1242               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1243               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1244                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1245                                            0);
1246               next0 = NAT44_ED_OUT2IN_NEXT_ICMP_ERROR;
1247               goto trace0;
1248             }
1249
1250           udp0 = ip4_next_header (ip0);
1251           tcp0 = (tcp_header_t *) udp0;
1252           icmp0 = (icmp46_header_t *) udp0;
1253           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1254
1255           if (is_slow_path)
1256             {
1257               if (PREDICT_FALSE (proto0 == ~0))
1258                 {
1259                   s0 =
1260                     nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1261                                                    thread_index, now, vm,
1262                                                    node);
1263                   if (!sm->forwarding_enabled)
1264                     {
1265                       if (!s0)
1266                         next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1267                       goto trace0;
1268                     }
1269                 }
1270
1271               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1272                 {
1273                   next0 = icmp_out2in_ed_slow_path
1274                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1275                      next0, now, thread_index, &s0);
1276                   goto trace0;
1277                 }
1278             }
1279           else
1280             {
1281               if (PREDICT_FALSE (proto0 == ~0))
1282                 {
1283                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1284                   goto trace0;
1285                 }
1286
1287               if (ip4_is_fragment (ip0))
1288                 {
1289                   next0 = NAT44_ED_OUT2IN_NEXT_REASS;
1290                   goto trace0;
1291                 }
1292
1293               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1294                 {
1295                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1296                   goto trace0;
1297                 }
1298             }
1299
1300           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1301                       ip0->protocol, rx_fib_index0, udp0->dst_port,
1302                       udp0->src_port);
1303
1304           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1305             {
1306               if (is_slow_path)
1307                 {
1308                   /* Try to match static mapping by external address and port,
1309                      destination address and port in packet */
1310                   e_key0.addr = ip0->dst_address;
1311                   e_key0.port = udp0->dst_port;
1312                   e_key0.protocol = proto0;
1313                   e_key0.fib_index = rx_fib_index0;
1314                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1315                                                  &twice_nat0, &lb_nat0,
1316                                                  &ip0->src_address,
1317                                                  &identity_nat0))
1318                     {
1319                       /*
1320                        * Send DHCP packets to the ipv4 stack, or we won't
1321                        * be able to use dhcp client on the outside interface
1322                        */
1323                       if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1324                                          && (udp0->dst_port ==
1325                                              clib_host_to_net_u16
1326                                              (UDP_DST_PORT_dhcp_to_client))))
1327                         {
1328                           vnet_feature_next (&next0, b0);
1329                           goto trace0;
1330                         }
1331
1332                       if (!sm->forwarding_enabled)
1333                         {
1334                           b0->error =
1335                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1336                           next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1337                         }
1338                       else
1339                         {
1340                           if (next_src_nat (sm, ip0, ip0->protocol,
1341                                             udp0->src_port, udp0->dst_port,
1342                                             thread_index, rx_fib_index0))
1343                             {
1344                               next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
1345                               goto trace0;
1346                             }
1347                           create_bypass_for_fwd (sm, ip0, rx_fib_index0,
1348                                                  thread_index);
1349                         }
1350                       goto trace0;
1351                     }
1352
1353                   if (PREDICT_FALSE (identity_nat0))
1354                     goto trace0;
1355
1356                   /* Create session initiated by host from external network */
1357                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1358                                                              e_key0, node,
1359                                                              thread_index,
1360                                                              twice_nat0,
1361                                                              lb_nat0, now);
1362
1363                   if (!s0)
1364                     {
1365                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1366                       goto trace0;
1367                     }
1368                 }
1369               else
1370                 {
1371                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1372                   goto trace0;
1373                 }
1374             }
1375           else
1376             {
1377               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1378             }
1379
1380           old_addr0 = ip0->dst_address.as_u32;
1381           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1382           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1383
1384           sum0 = ip0->checksum;
1385           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1386                                  dst_address);
1387           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1388             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1389                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1390                                    src_address);
1391           ip0->checksum = ip_csum_fold (sum0);
1392
1393           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1394             {
1395               old_port0 = tcp0->dst_port;
1396               new_port0 = tcp0->dst_port = s0->in2out.port;
1397
1398               sum0 = tcp0->checksum;
1399               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1400                                      dst_address);
1401               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1402                                      length);
1403               if (is_twice_nat_session (s0))
1404                 {
1405                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1406                                          s0->ext_host_nat_addr.as_u32,
1407                                          ip4_header_t, dst_address);
1408                   sum0 = ip_csum_update (sum0, tcp0->src_port,
1409                                          s0->ext_host_nat_port, ip4_header_t,
1410                                          length);
1411                   tcp0->src_port = s0->ext_host_nat_port;
1412                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1413                 }
1414               tcp0->checksum = ip_csum_fold (sum0);
1415               if (nat44_set_tcp_session_state_o2i
1416                   (sm, s0, tcp0, thread_index))
1417                 goto trace0;
1418             }
1419           else
1420             {
1421               udp0->dst_port = s0->in2out.port;
1422               if (is_twice_nat_session (s0))
1423                 {
1424                   udp0->src_port = s0->ext_host_nat_port;
1425                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1426                 }
1427               udp0->checksum = 0;
1428             }
1429
1430           /* Accounting */
1431           nat44_session_update_counters (s0, now,
1432                                          vlib_buffer_length_in_chain (vm,
1433                                                                       b0));
1434           /* Per-user LRU list maintenance */
1435           nat44_session_update_lru (sm, s0, thread_index);
1436
1437         trace0:
1438           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1439                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1440             {
1441               nat44_ed_out2in_trace_t *t =
1442                 vlib_add_trace (vm, node, b0, sizeof (*t));
1443               t->is_slow_path = is_slow_path;
1444               t->sw_if_index = sw_if_index0;
1445               t->next_index = next0;
1446               t->session_index = ~0;
1447               if (s0)
1448                 t->session_index = s0 - tsm->sessions;
1449             }
1450
1451           pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP;
1452           /* verify speculative enqueue, maybe switch current next frame */
1453           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1454                                            to_next, n_left_to_next,
1455                                            bi0, next0);
1456         }
1457
1458       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1459     }
1460
1461   vlib_node_increment_counter (vm, stats_node_index,
1462                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1463                                pkts_processed);
1464   return frame->n_vectors;
1465 }
1466
1467 static uword
1468 nat44_ed_out2in_fast_path_fn (vlib_main_t * vm,
1469                               vlib_node_runtime_t * node,
1470                               vlib_frame_t * frame)
1471 {
1472   return nat44_ed_out2in_node_fn_inline (vm, node, frame, 0);
1473 }
1474
1475 /* *INDENT-OFF* */
1476 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1477   .function = nat44_ed_out2in_fast_path_fn,
1478   .name = "nat44-ed-out2in",
1479   .vector_size = sizeof (u32),
1480   .format_trace = format_nat44_ed_out2in_trace,
1481   .type = VLIB_NODE_TYPE_INTERNAL,
1482   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1483   .error_strings = nat_out2in_ed_error_strings,
1484   .runtime_data_bytes = sizeof (snat_runtime_t),
1485   .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT,
1486   .next_nodes = {
1487     [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop",
1488     [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
1489     [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath",
1490     [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1491     [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out",
1492     [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass",
1493   },
1494 };
1495 /* *INDENT-ON* */
1496
1497 VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_node,
1498                               nat44_ed_out2in_fast_path_fn);
1499
1500 static uword
1501 nat44_ed_out2in_slow_path_fn (vlib_main_t * vm,
1502                               vlib_node_runtime_t * node,
1503                               vlib_frame_t * frame)
1504 {
1505   return nat44_ed_out2in_node_fn_inline (vm, node, frame, 1);
1506 }
1507
1508 /* *INDENT-OFF* */
1509 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1510   .function = nat44_ed_out2in_slow_path_fn,
1511   .name = "nat44-ed-out2in-slowpath",
1512   .vector_size = sizeof (u32),
1513   .format_trace = format_nat44_ed_out2in_trace,
1514   .type = VLIB_NODE_TYPE_INTERNAL,
1515   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1516   .error_strings = nat_out2in_ed_error_strings,
1517   .runtime_data_bytes = sizeof (snat_runtime_t),
1518   .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT,
1519   .next_nodes = {
1520     [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop",
1521     [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
1522     [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath",
1523     [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1524     [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out",
1525     [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass",
1526   },
1527 };
1528 /* *INDENT-ON* */
1529
1530 VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_slowpath_node,
1531                               nat44_ed_out2in_slow_path_fn);
1532
1533 static uword
1534 nat44_ed_out2in_reass_node_fn (vlib_main_t * vm,
1535                                vlib_node_runtime_t * node,
1536                                vlib_frame_t * frame)
1537 {
1538   u32 n_left_from, *from, *to_next;
1539   nat44_ed_out2in_next_t next_index;
1540   u32 pkts_processed = 0;
1541   snat_main_t *sm = &snat_main;
1542   f64 now = vlib_time_now (vm);
1543   u32 thread_index = vm->thread_index;
1544   snat_main_per_thread_data_t *per_thread_data =
1545     &sm->per_thread_data[thread_index];
1546   u32 *fragments_to_drop = 0;
1547   u32 *fragments_to_loopback = 0;
1548
1549   from = vlib_frame_vector_args (frame);
1550   n_left_from = frame->n_vectors;
1551   next_index = node->cached_next_index;
1552
1553   while (n_left_from > 0)
1554     {
1555       u32 n_left_to_next;
1556
1557       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1558
1559       while (n_left_from > 0 && n_left_to_next > 0)
1560         {
1561           u32 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
1562           vlib_buffer_t *b0;
1563           u32 next0;
1564           u8 cached0 = 0;
1565           ip4_header_t *ip0;
1566           nat_reass_ip4_t *reass0;
1567           udp_header_t *udp0;
1568           tcp_header_t *tcp0;
1569           icmp46_header_t *icmp0;
1570           clib_bihash_kv_16_8_t kv0, value0;
1571           snat_session_t *s0 = 0;
1572           u16 old_port0, new_port0;
1573           ip_csum_t sum0;
1574           snat_session_key_t e_key0, l_key0;
1575           lb_nat_type_t lb0;
1576           twice_nat_type_t twice_nat0;
1577           u8 identity_nat0;
1578
1579           /* speculatively enqueue b0 to the current next frame */
1580           bi0 = from[0];
1581           to_next[0] = bi0;
1582           from += 1;
1583           to_next += 1;
1584           n_left_from -= 1;
1585           n_left_to_next -= 1;
1586
1587           b0 = vlib_get_buffer (vm, bi0);
1588           next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
1589
1590           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1591           rx_fib_index0 =
1592             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1593                                                  sw_if_index0);
1594
1595           if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
1596             {
1597               next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1598               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_DROP_FRAGMENT];
1599               goto trace0;
1600             }
1601
1602           ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
1603           udp0 = ip4_next_header (ip0);
1604           tcp0 = (tcp_header_t *) udp0;
1605           icmp0 = (icmp46_header_t *) udp0;
1606           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1607
1608           reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
1609                                                  ip0->dst_address,
1610                                                  ip0->fragment_id,
1611                                                  ip0->protocol,
1612                                                  1, &fragments_to_drop);
1613
1614           if (PREDICT_FALSE (!reass0))
1615             {
1616               next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1617               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_REASS];
1618               nat_log_notice ("maximum reassemblies exceeded");
1619               goto trace0;
1620             }
1621
1622           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
1623             {
1624               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1625                 {
1626                   next0 = icmp_out2in_ed_slow_path
1627                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1628                      next0, now, thread_index, &s0);
1629
1630                   if (PREDICT_TRUE (next0 != NAT44_ED_OUT2IN_NEXT_DROP))
1631                     {
1632                       if (s0)
1633                         reass0->sess_index = s0 - per_thread_data->sessions;
1634                       else
1635                         reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1636                       reass0->thread_index = thread_index;
1637                       nat_ip4_reass_get_frags (reass0,
1638                                                &fragments_to_loopback);
1639                     }
1640
1641                   goto trace0;
1642                 }
1643
1644               make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1645                           ip0->protocol, rx_fib_index0, udp0->dst_port,
1646                           udp0->src_port);
1647
1648               if (clib_bihash_search_16_8
1649                   (&per_thread_data->out2in_ed, &kv0, &value0))
1650                 {
1651                   /* Try to match static mapping by external address and port,
1652                      destination address and port in packet */
1653                   e_key0.addr = ip0->dst_address;
1654                   e_key0.port = udp0->dst_port;
1655                   e_key0.protocol = proto0;
1656                   e_key0.fib_index = rx_fib_index0;
1657                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1658                                                  &twice_nat0, &lb0, 0,
1659                                                  &identity_nat0))
1660                     {
1661                       /*
1662                        * Send DHCP packets to the ipv4 stack, or we won't
1663                        * be able to use dhcp client on the outside interface
1664                        */
1665                       if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1666                                          && (udp0->dst_port
1667                                              ==
1668                                              clib_host_to_net_u16
1669                                              (UDP_DST_PORT_dhcp_to_client))))
1670                         {
1671                           vnet_feature_next (&next0, b0);
1672                           goto trace0;
1673                         }
1674
1675                       if (!sm->forwarding_enabled)
1676                         {
1677                           b0->error =
1678                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1679                           next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1680                         }
1681                       else
1682                         {
1683                           if (next_src_nat (sm, ip0, ip0->protocol,
1684                                             udp0->src_port, udp0->dst_port,
1685                                             thread_index, rx_fib_index0))
1686                             {
1687                               next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
1688                               goto trace0;
1689                             }
1690                           create_bypass_for_fwd (sm, ip0, rx_fib_index0,
1691                                                  thread_index);
1692                           reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1693                           nat_ip4_reass_get_frags (reass0,
1694                                                    &fragments_to_loopback);
1695                         }
1696                       goto trace0;
1697                     }
1698
1699                   if (PREDICT_FALSE (identity_nat0))
1700                     {
1701                       reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1702                       goto trace0;
1703                     }
1704
1705                   /* Create session initiated by host from external network */
1706                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1707                                                              e_key0, node,
1708                                                              thread_index,
1709                                                              twice_nat0, lb0,
1710                                                              now);
1711                   if (!s0)
1712                     {
1713                       b0->error =
1714                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1715                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1716                       goto trace0;
1717                     }
1718                   reass0->sess_index = s0 - per_thread_data->sessions;
1719                   reass0->thread_index = thread_index;
1720                 }
1721               else
1722                 {
1723                   s0 = pool_elt_at_index (per_thread_data->sessions,
1724                                           value0.value);
1725                   reass0->sess_index = value0.value;
1726                 }
1727               nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
1728             }
1729           else
1730             {
1731               if (reass0->flags & NAT_REASS_FLAG_ED_DONT_TRANSLATE)
1732                 goto trace0;
1733               if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
1734                 {
1735                   if (nat_ip4_reass_add_fragment
1736                       (reass0, bi0, &fragments_to_drop))
1737                     {
1738                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_FRAG];
1739                       nat_log_notice
1740                         ("maximum fragments per reassembly exceeded");
1741                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1742                       goto trace0;
1743                     }
1744                   cached0 = 1;
1745                   goto trace0;
1746                 }
1747               s0 = pool_elt_at_index (per_thread_data->sessions,
1748                                       reass0->sess_index);
1749             }
1750
1751           old_addr0 = ip0->dst_address.as_u32;
1752           ip0->dst_address = s0->in2out.addr;
1753           new_addr0 = ip0->dst_address.as_u32;
1754           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1755
1756           sum0 = ip0->checksum;
1757           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1758                                  ip4_header_t,
1759                                  dst_address /* changed member */ );
1760           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1761             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1762                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1763                                    src_address);
1764           ip0->checksum = ip_csum_fold (sum0);
1765
1766           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
1767             {
1768               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1769                 {
1770                   old_port0 = tcp0->dst_port;
1771                   tcp0->dst_port = s0->in2out.port;
1772                   new_port0 = tcp0->dst_port;
1773
1774                   sum0 = tcp0->checksum;
1775                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1776                                          ip4_header_t,
1777                                          dst_address /* changed member */ );
1778
1779                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1780                                          ip4_header_t /* cheat */ ,
1781                                          length /* changed member */ );
1782                   if (is_twice_nat_session (s0))
1783                     {
1784                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1785                                              s0->ext_host_nat_addr.as_u32,
1786                                              ip4_header_t, dst_address);
1787                       sum0 = ip_csum_update (sum0, tcp0->src_port,
1788                                              s0->ext_host_nat_port,
1789                                              ip4_header_t, length);
1790                       tcp0->src_port = s0->ext_host_nat_port;
1791                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1792                     }
1793                   tcp0->checksum = ip_csum_fold (sum0);
1794                 }
1795               else
1796                 {
1797                   old_port0 = udp0->dst_port;
1798                   udp0->dst_port = s0->in2out.port;
1799                   if (is_twice_nat_session (s0))
1800                     {
1801                       udp0->src_port = s0->ext_host_nat_port;
1802                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1803                     }
1804                   udp0->checksum = 0;
1805                 }
1806             }
1807
1808           /* Accounting */
1809           nat44_session_update_counters (s0, now,
1810                                          vlib_buffer_length_in_chain (vm,
1811                                                                       b0));
1812           /* Per-user LRU list maintenance */
1813           nat44_session_update_lru (sm, s0, thread_index);
1814
1815         trace0:
1816           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1817                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1818             {
1819               nat44_reass_trace_t *t =
1820                 vlib_add_trace (vm, node, b0, sizeof (*t));
1821               t->cached = cached0;
1822               t->sw_if_index = sw_if_index0;
1823               t->next_index = next0;
1824             }
1825
1826           if (cached0)
1827             {
1828               n_left_to_next++;
1829               to_next--;
1830             }
1831           else
1832             {
1833               pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP;
1834
1835               /* verify speculative enqueue, maybe switch current next frame */
1836               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1837                                                to_next, n_left_to_next,
1838                                                bi0, next0);
1839             }
1840
1841           if (n_left_from == 0 && vec_len (fragments_to_loopback))
1842             {
1843               from = vlib_frame_vector_args (frame);
1844               u32 len = vec_len (fragments_to_loopback);
1845               if (len <= VLIB_FRAME_SIZE)
1846                 {
1847                   clib_memcpy (from, fragments_to_loopback,
1848                                sizeof (u32) * len);
1849                   n_left_from = len;
1850                   vec_reset_length (fragments_to_loopback);
1851                 }
1852               else
1853                 {
1854                   clib_memcpy (from,
1855                                fragments_to_loopback + (len -
1856                                                         VLIB_FRAME_SIZE),
1857                                sizeof (u32) * VLIB_FRAME_SIZE);
1858                   n_left_from = VLIB_FRAME_SIZE;
1859                   _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
1860                 }
1861             }
1862         }
1863
1864       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1865     }
1866
1867   vlib_node_increment_counter (vm, nat44_ed_out2in_reass_node.index,
1868                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1869                                pkts_processed);
1870
1871   nat_send_all_to_node (vm, fragments_to_drop, node,
1872                         &node->errors[NAT_OUT2IN_ED_ERROR_DROP_FRAGMENT],
1873                         NAT44_ED_OUT2IN_NEXT_DROP);
1874
1875   vec_free (fragments_to_drop);
1876   vec_free (fragments_to_loopback);
1877   return frame->n_vectors;
1878 }
1879
1880 /* *INDENT-OFF* */
1881 VLIB_REGISTER_NODE (nat44_ed_out2in_reass_node) = {
1882   .function = nat44_ed_out2in_reass_node_fn,
1883   .name = "nat44-ed-out2in-reass",
1884   .vector_size = sizeof (u32),
1885   .format_trace = format_nat44_reass_trace,
1886   .type = VLIB_NODE_TYPE_INTERNAL,
1887   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1888   .error_strings = nat_out2in_ed_error_strings,
1889   .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT,
1890   .next_nodes = {
1891     [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop",
1892     [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
1893     [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath",
1894     [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1895     [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out",
1896     [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass",
1897   },
1898 };
1899 /* *INDENT-ON* */
1900
1901 VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_reass_node,
1902                               nat44_ed_out2in_reass_node_fn);
1903
1904 /*
1905  * fd.io coding-style-patch-verification: ON
1906  *
1907  * Local Variables:
1908  * eval: (c-set-style "gnu")
1909  * End:
1910  */